Viinikiveä

Viinikivi, scientifically known as potassium bitartrate, is a crystalline deposit that forms in wine during the winemaking process. It is a salt of tartaric acid, a naturally occurring organic acid found in grapes. When grapes ferment, tartaric acid reacts with potassium ions to form potassium bitartrate. As the wine ages, particularly in cool conditions, this salt precipitates out of the solution and can accumulate on the bottom and sides of wine barrels or bottles, forming what is commonly referred to as wine crystals or sediment.

Viinikivi is harmless and does not affect the quality or taste of the wine. In fact, its presence is often seen as an indicator of a natural, minimally processed wine. The crystals are edible, although they can have a slightly gritty texture if consumed. In culinary applications, viinikivi is widely known as cream of tartar. It is used as a leavening agent in baking, helping to stabilize egg whites and prevent sugar crystallization. It is also employed in confectionery and some food preservation techniques. Historically, viinikivi was a significant source of tartaric acid, which has various industrial uses beyond food. Its extraction from wine lees, a byproduct of winemaking, was a common practice for centuries.